New smart solutions could replace current infection testing

New technology could pave the way to a future of rapid testing in hospitals and at home for both COVID and urinary tract infection. It could also be used to keep track of blood sugar levels during operations and wireless monitoring of various bacterial infections.

In her research, "Electrochemical (bio)sensors operating in human physiological fluids," Carolin Psotta details how electrochemical biosensors can detect, predominantly, bacteria and viruses in human fluids, such as blood, urine, plasma, and saliva.

"My hope is that thanks to these biosensors we can make the tests we use today—which can take several days—easier and more efficient, both for private individuals and healthcare systems," she says, adding: the samples were tested under homeostatic conditions, which means that properties during the measurement are tried to keep the same as inside the body. The enzyme on the sensor converts the glucose in the blood and prompts a reaction that the sensor registers.

"There are different types of biosensors; the fact that it is electrochemical means that an electrode on the surface picks up biochemical events from its surroundings."

As part of her project, she has developed four types of sensors that can be used for different purposes. The first can detect COVID and for it Psotta used existing studies that show that the composition of the saliva changes after a COVID infection. She used a technology called the 'electronic tongue' for her sensor which is made up of six different metals, each of which give different signals, and show if the saliva comes from an individual with COVID.

Another of her sensors can monitor blood glucose levels. It is an enzyme-based biosensor which was tested on human plasma and undiluted blood: "The sensor can, for example, be used in an operating theatre to monitor the patient's blood sugar level, which often varies when the body has a stress reaction."

Psotta's third sensor can detect urinary tract infections (UTIs). This biosensor was developed to detect elevated levels of e. Coli bacteria in urine. It can also transmit information wirelessly to, for example, a smart device. "One area of use could be putting the sensor in a diaper where there is an increased risk of a UTI. The healthcare staff can then monitor the levels and detect the bacteria early."

The fourth sensor can identify three different types of bacterial based on metabolic changes in artificial urine. Here, too, the electronic tongue technology is applied to distinguish bacteria free from bacteria infected artificial urine.

"By seeing which molecules are either present or missing in the urine, we also know which bacteria are active there." Psotta now hopes that her research will lead to clinical trials so that the biosensors can be further developed and eventually reach the market.

More information:
Magnus Falk et al, Non-Invasive Electrochemical Biosensors Operating in Human Physiological Fluids, Sensors (2020). DOI: 10.3390/s20216352

Provided by Malmö University